1. Field of the Invention
The present invention relates to a disk device that can determine whether a normal disk is installed to a normal position by use of an optical detecting member and in addition, can save power consumption during waiting for disk insertion.
2. Description of the Related Art
A slot-in type disk device to be inserted from a slit-like insertion port formed in a casing is equipped with a detecting unit disposed inside the insertion port. If the detecting unit detects disk insertion, a conveying mechanism including a transport roller starts operating and transports the disk into the device. Here, it is necessary to determine whether the disk inserted from the insertion port and transported is a normal disk. For example, provided that a normal disk has a diameter of 12 cm, when a disk having a diameter of 8 cm, a disk that is not circular in outer shape, or a rectangular card is inserted, it is necessary to determine the disk or card as a foreign material, not a normal disk, and to immediately discharge the disk or card from the insertion port.
A disk device disclosed in Japanese Unexamined Patent Application Publication No. 2006-99833 is equipped with a pair of detecting members disposed inside an insertion port and sliding along an outer edge of an inserted disk. The pair of detecting members is biased to get close to each other by means of spring force. If it is detected that the detecting members has been pressed by the outer edge of a disk and moved by a predetermined distance, it is determined that any disk has been inserted from the insertion port. Then, a conveying mechanism starts operating. After that, during a period where the conveying mechanism transports the disk, the pair of detecting members slides along the outer edge of the disk, and a distance between the members is changed. By detecting the change in distance, whether a normal disk has been transported in a normal way is determined.
A disk device disclosed in Japanese Unexamined Patent Application Publication No. 2005-251329 employs plural optical detecting members as a detecting unit. In the disk device, if a disk blocks an optical path of each detecting member, it is determined that any disk has been inserted. Then, a conveying mechanism starts operating to convey the disk into the device. By monitoring a combination of detection outputs from the optical detecting members during conveyance of the disk into the device, it is determined whether a normal disk has been transported in a normal way.
The disk device disclosed in Japanese Unexamined Patent Application Publication No. 2006-99833 has the following problem: because the detecting members keep sliding along the outer edge of the disk during disk transport, a high resistance is applied when the disk is transported into the device and in addition, if the outer edge of the inserted disk is not round or a card or the like is inserted by mistake, such a disk or card is caught on the detecting members and then could not be taken out from the insertion port.
Further, the disk device designed to detect a disk with an optical detecting member as disclosed in Japanese Unexamined Patent Application Publication No. 2005-251329 involves the following defect: because the device needs to continuously supply a power to the optical detecting member during waiting for disk insertion so as to detect disk insertion when a disk is inserted, a large amount of power is consumed during waiting for disk insertion. For example, if the device is an in-vehicle disk device, a battery power is excessively consumed while a vehicle engine is stopped.